package test;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Tool {
	public static void main(String args[]) {
	      String s = "-1";
	     System.out.println(MD5Tool.stringToMD5(s));
	   }


	 public static String stringToMD5(String plainText) {
	         byte[] secretBytes = null;
	         try {
	                secretBytes = MessageDigest.getInstance("md5").digest(
	                     plainText.getBytes());
	         } catch (NoSuchAlgorithmException e) {
	             throw new RuntimeException("没有这个md5算法！");
	         }
	         String md5code = new BigInteger(1, secretBytes).toString(16);//转换成16进制
	       for (int i = 0; i < 32 - md5code.length(); i++) {
	         //如果产生的数据长度不是32，则前面补0
	             md5code = "0" + md5code;
	         }
	         return md5code;
	     }
}
